Abstract: Welding pool tracking technology is one of the key core technologies in the field of welding automation,and its purpose is to automatically adjust the welding parameters and ensure the welding quality through real-time monitoring of the weld pool status during the welding process. The weld pool image sequence is collected by the method of robot automatic welding, and the CCD filter camera is used to collect the melt pool image sequence,and then the melt pool image sequence is analyzed by Halcon software, and the image is tracked by the inter-frame difference method and optical flow method. VS software was mixed with Halcon for interface design to realize the output of the program window. Experiments results show that the two algorithms have a good display effect for the visual tracking of the weld pool image sequence, and the research on the visual tracking of the melt pool has a promising application prospect for the realization of automatic welding.